Clutching device for washing and drying machines



Sept. 19, 1961 J. COENDERS 3,000,483

CLUTCHING DEVICE FOR WASHING AND DRYING MACHINES Filed Dec. 1, 1959 Jnvemo r:

b JOl/A/V/V COE/VDERS United States Patent @fifice 3,000,483 PatentedSept. 19, 1961 3,000,483 CLUTCHING DEVICE FOR WASHING AND DRYINGMACHINES Johann Coenders, Hans Waldesheim, Krefeld-Traar, Germany FiledDec. 1, 1959, Ser. No. 856,484

Claims priority, application Germany Dec. 5, 1958 2 Claims. (Cl.192-103) In Washington machines which are provided with a drum both forwashing and for centrifuging, the drum must be rotated at a relativelylow speed during the washing process to obtain satisfactory results, butthe speed of rotation must be much higher for the centrifugal dryingprocess in order to achieve satisfactory extraction of the water. Ingeneral, the speed of the drum should not exceed 45 revolutions perminute during the washing process but should rotate at about 600revolutions per minute during centrifuging. Consequently, the ratiobetween speed of rotation during washing and speed of rotation duringcentrifuging is about 1 to 13. This ratio cannot be achieved by usingonly the known drive motors for automatic washing machines such astwo-stage, polereversible motors, on their own.

A driving mechanism for washing and centrifuging machines has thereforebecome known in which the drum is driven at the differing speedsrequired for washing and centrifuging by means of a driving motor whichoperates only over a small speed range, for example a polereversiblemotor, and which operates through either one of two reduction geartrains arranged in parallel. A centrifugally operated control deviceautomatically causes the motor to drive through one gear train or theother in dependence on the speed of the driving motor. By means of sucha driving mechanism, it is possible to increase the relatively smallrange of speeds of the driving motor to such an extent that the washingand centrifuging drum is driven at the required speeds for the differentoperations. The centrifugally operated control device automaticallyeffects the changing over of the gearing in dependence on the speed ofrevolution of the drive motor. The present invention relates to awashing machine having a driving mechanism of this nature.

Known driving mechanisms of this nature have the disadvantage that thereduction gearing is complex and requires an overriding clutch to beincorporated to allow the gear train for the washing process to run idlywhen the gear train for centrifuging is in operation. This is avoided bythe present invention. To this end, according to the present invention,the centrifugally operated control device comprises centrifugal controlweights radially movably mounted on members fixed to a shaft whichrotates at a speed dependent on that of the motor, the weights beingacted upon by springs in a direction opposite to that of the centrifugalforces, and two driving rings connected one to each of the gear trainsand arranged to co-operate with the centrifugal weights, the strength ofthe springs being such that at a lower speed of rotation of the shaftthe weights are moved inwardly by the springs and contact one drivingring to transmit a drive from the shaft to one reduction gear train andat a higher speed of rotation of the shaft the weights are movedoutwardly against the springs by centrifugal force and contact the otherdriving ring to transmit a drive from the shaft to the other reductiongear train.

This ensures that when one gear train is coupled to the driving motor,the centrifugally operated control device will at the same time uncouplethe other gear train, which dispenses with the arrangement, which hashitherto been necessary, of providing an overriding clutch in thereduction gearing. This results in a considerably simpler drivingdevice, which is also less liable to break-downs.

Preferably, the rings are in the form of drums which are rotatablymounted side by side on the shaft and enclose the members fixed to theshaft, the members being radially extending arms on the ends of whichthe weights in the form of two-armed levers are pivoted, the arms beingof unequal weights, the lighter of which lie inside one drum and areurged outwards by springs and the heavier of which are axially ofisetfrom the lighter arms and lie inside the other drum. This results in avery space saving arrangement for the centrifugally operated controldevice which, owing to the offset arrangement of the lever arms whichact as centrifugal Weights, will act alternately on the drive drum ofone gear train or the other, according to the speed of the drivingshaft, while the drive drum of the other gear train is uncoupled.

A clutching device for a washing machine in accordance with theinvention will now be described, by way of example, with reference tothe accompanying drawings in which:

FIGURE 1 is a side elevation of the centrifugally operated controldevice with parts removed;

FIGURE 2 is a section as seen in the direction of the arrows on the lineAA in FIGURE 1;

FIGURE 3 is a side elevation of a part of the device shown in FIGURES 1and 2; and,

FIGURE 4 is a plan of the part shown in FIGURE 3.

As shown in FIGURES 1 and 2, four driving arms 1 of the centrifugallyoperated control device are rigidly connected on a shaft 2 of thedriving motor, which is not shown in the drawing. A two-armedcentrifugal weight lever 4 is pivotally mounted on the end of each ofthe driving arms 1 by means of a bolt 3. The form of the centrifugalweight levers is indicated in FIGURES 3 and 4. The arms 5 of the leversare lighter than the arms 6, and each of the lighter lever arms 5 isacted upon by a radially disposed compression spring 7. Driving drums 8,10 which are rotatably mounted on the driving shaft 2., are disposed oneon each side of the driving arms 1. The arms 5 and 6 of each centrifugalweight lever 4 are axially offset from one another as seen in FIGURE 4,in such a manner that each arm can lie with its outer surface againstthe inner surface of its associated driving drum 8 or 10. The lightlever arms 5 are inside the inner circumference of the driving drum 8towards which they are pressed by the compression springs 7. When theforces of the springs 7 overcome the centrifugal forces on the arms 6the driving shaft 2 is frictionally connected to the driving drum 8 and,by way of a toothed wheel 9 integral with the drum 8, the rotation ofthe motor, for example 750 revolutions per minute, is transmitted withthe necessary speed reduction for the washing process to the washingdrum, which is not shown. The compression in the springs 7 is such thatthe pressure required between the arms 5 and the driving drum 8 totransmit the power of the washing drum is produced and in addition thecentrifugal force on the heavier arms 6 produced at a motor speed of 750revolutions per minute is overcome.

If the driving motor, which is preferably a two-speed or variable speedmotor which may also be reversible, is switched over from 750 to 1500revolutions per minute by changing the speeds, then the heavier arms 6of the centrifugal weight levers 4 will be pressed against the drivingdrum 10 because the springs 7 are overcome by the increased centrifugalforce on the arms 6 which is proportional to the square of the speed ofrevolution of the shaft 2. Thus the shaft 2 is frictionally connected tothe drum 10 and the speed of the motor of 1500 revolutions per'minute istransmitted with the necessary reduction in speed, through a toothedwheel 11 on the drum 10 to the washing drum which now carries out thecentrifugal drying process. As the arms 6 are pressed against 10 saidshaft and having inner peripheral faces adjacent respectively to saidheavier and said lighter arms, compression spring means for urging thelighter of said arms into engagement With the peripheral face of itsrespective drum during a low rate of revolutions, said other heavierarms being adapted to engage by centrifugal force with the peripheralface of its respective drum at a higher rate of revolutions.

2. Centrifugal force coupling according to claim 1, wherein said weightlevers are of the shape of a comma.

References Cited in the file of this patent UNITED STATES PATENTS2,275,046 Harris Mar. 3, 1942 2,639,794 McNairy May 26, 1953 2,881,633Warhus Apr. 14, 1959 ere

